JP2003138115A - Polytrimethylene terephthalate composition and method of production for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mass-colored polytrimethylene terephthalate composition containing carbon black uniformly dispersed in the resin, and to provide a method of production for the same. SOLUTION: This composition includes the polytrimethylene terephthalate as a principal ingredient and 5-50 wt.% based on the total weight of the resin composition of specific carbon black absorbing benzoic acid on the surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called stagnation masterbatch composition containing polyester with a high concentration of carbon black and a method for producing the same.

[0002]

2. Description of the Related Art Polytrimethylene terephthalate obtained by polycondensing a lower alcohol of terephthalic acid such as terephthalic acid or dimethyl terephthalate and trimethylene glycol (1,3-propanediol) has a low elastic modulus (softness). It is an epoch-making material that has properties similar to polyamide, such as excellent texture) and excellent elastic recovery, and properties similar to polyethylene terephthalate, such as light resistance, heat setting, dimensional stability, and low water absorption. Is utilized for BCF carpets, brushes, tennis guts, etc. (see Japanese Patent Laid-Open Nos. 9-3724, 8-173244, 5-2626282, etc.).

However, although the dyeability with disperse dyes is superior to that of polyethylene terephthalate, it cannot be denied that it is still insufficient because of being polyester. In order to eliminate such a defect of dyeability, polyethylene terephthalate is often used as a so-called moist-applied polyester in which a pigment is mixed for clothing or non-clothing. Market development is gradually progressing for the use of polytrimethylene terephthalate for the primary coating.

However, the actual condition is that the original polytrimethylene terephthalate is inferior in color tone to polyethylene terephthalate and the dispersibility of carbon black is insufficient. Further, since polytrimethylene terephthalate is weak against heat as compared with polyethylene terephthalate, there is a problem that a cyclic dimer is likely to be generated together with coloring, and there are many foreign matters in the spinneret in the spinning process.

On the other hand, in the case of producing a depositing molded article in which carbon black and the like are sufficiently dispersed, there is a method in which a master polymer containing a high concentration of a pigment is prepared, and this is added to a base polymer containing no pigment to perform molding. Widely adopted.

[0006] Various methods for producing the uncoated polyester have been proposed, but the industrially practiced methods include a polymerization addition method of adding a pigment at the time of polymerization of the polyester, a kneader of a polyester and a pigment, and a Banbury mixer. It is roughly classified into a kneading method in which melt mixing is performed with the like.

However, the former addition method at the time of polymerization causes a large loss due to a change in concentration, and it is difficult to cope with small quantity production of a wide variety of products due to stains due to pigments in a reactor. There is a problem that it is difficult to disperse highly uniformly in it, or it takes a long time, and it is difficult to disperse the pigment highly uniformly, especially when manufacturing a master polymer with a high pigment concentration. Met. Further, if the residence time is increased in order to highly disperse the pigment, the viscosity is lowered, and the shearing force required for kneading is not applied, but the quality such as hue is further deteriorated. It was

[0008]

An object of the present invention is to provide a polytrimethylene terephthalate masterbatch having a high pigment concentration in which a carbon black pigment is highly uniformly dispersed by a dispersant and a kneading method, and a method for producing the same. It is a thing.

[0009]

In order to solve the above problems, the present inventors have examined the characteristics of polyester and carbon black used for kneading, and as a result, have a specific particle diameter and contain coarse particles. However, by using carbon black whose adsorption characteristics are controlled, and pre-adsorbing this with benzoic acid and kneading with a polyester of a specific particle size and a kneading extruder, it is possible to obtain good hue and pigment dispersibility. The present invention has been accomplished by finding that a primed poly (trimethylene terephthalate) composition which is excellent and in which the formation of cyclic dimers is suppressed can be obtained. That is, an object of the present invention is a polyester resin composition containing polytrimethylene terephthalate as a main component, wherein carbon black having benzoic acid adsorbed on the surface thereof is added in an amount of 5 to 50% by weight based on the total weight of the resin composition. %, And the content of cyclic dimer is less than 1%, which can be achieved by a polytrimethylene terephthalate resin composition.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below.

In the present invention, carbon black of 5 to 5 is used.
It must be contained in the range of 40% by weight.
Since the primary polymer is often used as a so-called master chip, if it is less than 5%, it is economically disadvantageous, and if it exceeds 40%, agglomeration of carbon black becomes remarkable, which is not preferable.

The carbon black used in the present invention preferably has an average particle size in the range of 10 to 50 nm. If it is less than 10 nm, the depth of color as the primary fiber is lacked, and the surface activity is large, which accelerates the generation of oligomers, which is not preferable. If it is larger than 50 nm, it grows into secondary particles in the composition to become foreign matter,
It is not preferable because it deteriorates the process condition.

It is desirable that the carbon black is a powder having a specific particle size or more and few coarse particles. According to the study by the present inventors, it has been found that the longest grain size is not the average grain size and is related to the process tone. The longest particle size means that when carbon black particles are approximated by a circumscribed ellipse,
The major axis of the ellipse. It is desirable that the number of coarse particles having a maximum particle size of more than 0.2 mm is 1/200 g powder or less.

If the number of the coarse particles is large, the process condition is deteriorated by itself, and the particles further grow as foreign particles during the molding process, which is not preferable. The carbon black particles used in the present invention have an iodine adsorption amount of 80 to 200 mg.
/ G is preferable. Iodine adsorption amount is 80 mg /
If it is less than g, benzoic acid is not adsorbed, the dispersibility of carbon black, the deterioration of hue and the amount of cyclic oligomer are increased, which is not preferable. On the other hand, if the amount exceeds 200 mg, agglomerated particles are likely to grow, the amount of benzoic acid required to prevent this increases, which is uneconomical, which is not preferable.

In the present invention, it is necessary to adsorb benzoic acid on carbon black and then surface-treat it.
By adsorbing benzoic acid on the surface, generation of cyclic oligomers can be suppressed and deterioration of the hue of the polymer can be prevented. The mechanism of this action is not clear, but it is considered as follows.

That is, benzoic acid is in the adsorption equilibrium on the carbon surface, while the cyclic dimer in the molding process is in equilibrium with the molten polymer. The benzoic acid adsorbed on the carbon surface has a terminal carboxyl group, and therefore contributes to a decrease in the ester concentration of the cyclic dimer in equilibrium. Therefore, it is considered that the generation of the cyclic dimer during the melt molding is suppressed.

Further, it is considered that the presence of the carboxyl group of benzoic acid complements the radicals that cause coloring and suppresses the oxidative deterioration of the glycolic terminal of polytrimethylene terephthalate. Further, when there is an active or impure component on the carbon surface, it is considered that the active groups are blocked with benzoic acid to suppress the decomposition and deterioration of polytrimethylene terephthalate.

The primary dyed polyester in the present invention is pelletized by a conventional method and used as a master chip. Intrinsic viscosity when pelletized 0.7-0.9
It is preferably in the range of. When the intrinsic viscosity is less than 0.7, when mixed with the base polymer, the viscosity is largely decreased, and strength and other physical properties of the molded product cannot be sufficiently secured, which is not preferable. On the other hand, if the intrinsic viscosity is 0.9 or more, the melt viscosity becomes too high and the mixing with the base polymer is not sufficiently uniform.

The color tone b of the polytrimethylene terephthalate composition in the present invention is more preferably in the range of 2 to 6. When the b value exceeds 6, yellowishness is conspicuous, and the color tone of the obtained product becomes poor. Also, the b value is 2
When it is less than the above range, a whitish sensation is given and the depth of the original coloring of carbon black is reduced, which is not preferable.

The composition of the present invention can be manufactured by the following manufacturing method. The raw material polyester is preferably pulverized to have a particle diameter of 2 mm or less. If the particle diameter exceeds 2 mm, the titanium dioxide pigment cannot be uniformly mixed and is likely to be separated to cause uneven density or poor dispersion. .
However, if the particles are made finer than necessary, the crushing cost will increase and the cost will increase, so the particle diameter is 1.2 to 1.
It is preferably 7 mm.

In the present invention, the polyester powder and the carbon black pigment need not be separately supplied to the kneading extruder, but premixed and then supplied to the kneading extruder. When the polyester powder and the carbon black pigment are separately fed to the kneading extruder and kneaded, the polyester powder and the carbon black pigment are not uniformly mixed, resulting in uneven density and poor dispersion, thereby obtaining a master polyester uniformly dispersed. I can't.

In the present invention, benzoic acid is adsorbed in premixing. Benzoic acid needs to be performed at a temperature of 100 to 120 ° C. When the temperature is lower than 100 ° C, benzoic acid is not sublimated sufficiently and the adsorptivity is significantly deteriorated. Again 160
If it exceeds ℃, it may partly decompose, and it may cause coloration or irritating odor, which may cause problems in the working environment.
The preferred adsorption temperature is in the range of 100 to 120 ° C.

In the pre-mixing, the dry polyester powder and the titanium dioxide pigment are fed to a high-speed stirring mixer, and the rotation speed is 80.
At 0 to 1500 rpm and a temperature of 100 to 120 ° C., 3 to
It is preferably carried out by stirring and mixing for 15 minutes. If the rotation speed of the stirrer is too low or the mixing time is too short, uniform mixing becomes difficult, and conversely, if the rotation speed is too high or the mixing time is too long, the polyester heat The above-mentioned number of rotations and mixing time are preferable because they cause decomposition and cause coloring.

As a result of the study by the present inventors, particularly good adsorption is exhibited when the residence time satisfies the following conditions.

[0025]

[Equation 2]

Here, as the mixer, Mitsui Miike Seisakusho Co., Ltd .: Henschel mixer, Kawata Co., Ltd .: Super mixer, Moriyama Seisakusho's MS type high-speed mixer can be used. .

The mixing ratio of the polyester powder and the carbon black pigment is set to (80:20) to (40:60), which is generally used as a master dye master polymer. When the concentration of the carbon black pigment is less than 20%, the kneading time per unit weight of the carbon black becomes long and the manufacturing cost becomes high. When it exceeds 60%, the carbon black pigment is not well dispersed in the polymer or the kneading extruder is used. The fluidity of the polymer inside becomes poor, and the load on the kneading extruder becomes high, making it impossible to knead. The preferable mixing ratio of the polyester powder and the carbon black pigment is (70:30) to (45: 5).
5).

The weight ratio of benzoic acid to carbon black is preferably 0.1 to 5% by weight. If it is less than 0.1, the amount of adsorption is too small to speak of the effect, and even if benzoic acid exceeds 5% of carbon black, it is in the equilibrium adsorption region and the effect is not improved.

According to the studies by the present inventors, the treatment time of benzoic acid on carbon black greatly affects the adsorption rate,
It has been found that the preferred treatment time depends on the benzoic acid to carbon black weight ratio as well as the premix temperature. That is, it is necessary to extend the adsorption time as the charged amount of benzoic acid increases, and if the treatment time is insufficient, the adsorption of benzoic acid is insufficient and the coating effect is lost, which is not preferable. However, if the treatment time is too long, benzoic acid will be desorbed, which is not preferable. As a result of studies by the present inventors, the range shown in the following formula is preferable.

[0030]

[Equation 3]

As the kneading extruder, a screw type biaxial same-direction or different-direction kneading extruder is preferably used, but a single-screw kneading extruder may be used.

For example, HYPER manufactured by Kobe Steel Ltd.
When a master polymer having a mixing ratio of polyester powder and titanium dioxide pigment of 50:50 is produced by using a kneading extruder of KTX-46 (screw diameter 46 mmφ, biaxial, rotating in the same direction), preferable conditions for kneading are: , Kneading temperature; 250 to 280 ° C., extrusion amount; 30 to 70 kg /
hr, screw rotation speed; 80 to 200 rpm.

When a single-screw kneading extruder is used, for example,
When producing the above master polymer using GT-65 manufactured by Plastic Engineering Laboratory Co., Ltd., preferable conditions during kneading are kneading temperature: 240 to 270 ° C., extrusion amount:
50-100 kg / hr, screw rotation speed; 100-
It is 200 rpm.

[0034]

EXAMPLES Next, the present invention will be described in detail with reference to examples. In the examples, "parts" represent parts by weight, and the measurement and evaluation methods are as follows. (1) Average particle diameter and longest particle diameter of carbon black: A photograph taken by an optical microscope AX-70 manufactured by Olympus Co., Ltd. is read by an image analyzer LUZEX-FS manufactured by Nireco Co., Ltd., and a circle equivalent radius analysis mode and a maximum are obtained. The longest particle size was determined using the diameter analysis mode. (2) Intrinsic viscosity: Determined by an ordinary method at 35 ° in o-chlorophenol. (3) Color tone b: Color machine CR manufactured by Nippon Denshoku Industries Co., Ltd.
It was measured at -200. (4) Cyclic dimer: Hexafluoroisopropanol / chloroform were dissolved in a mixed solution of volume ratio (1: 1), and quantified by HPLC.

[Example 1 and Comparative Example 1] The intrinsic viscosity was 1.
0, the polytrimethylene terephthalate powder having the particle size shown in Table 1 and the carbon black pigment having the characteristics shown in Table 1 were charged into the Henschel mixer at the mixing ratio shown in Table 1, and the stirring rotation speed was 1200 rpm. After stirring and mixing at 110 ° C. for a residence time of 8 minutes, the mixture was supplied to a screw type twin-screw kneading extruder (KTX-46 manufactured by Kobe Steel, Ltd.),
The temperature of the kneading part is 265 ° C, the extrusion rate is 50 kg / h
r and the screw rotation speed were set to 300 rpm, and kneading was performed continuously to obtain master pellets. The results are shown in Table 1.

[Example 2 and Comparative Example 2] The intrinsic viscosity was 0.
At 68, polyethylene terephthalate powder having the particle size shown in Table 1 and the carbon black pigment having the properties shown in Table 1 were charged into the Henschel mixer at the mixing ratio shown in Table 1, and the stirring rotation speed was 1200 rpm and the residence time was After stirring and mixing under the condition of 8 minutes, the mixture was fed to a screw type single-screw kneading extruder (GT-65A manufactured by Plastic Engineering Laboratory Co., Ltd.), the temperature of the kneading part was 260 ° C., and the extrusion amount was 10
A master pellet was obtained by continuously kneading the mixture at 0 kg / hr and a screw rotation speed of 150 rpm. The results are shown in Table 1.

[0037]

[Table 1]

[0038]

According to the present invention, a master dyed master polyester in which carbon black pigment is highly uniformly dispersed in polyester can be easily obtained. When this masterbatch is used, especially when it is used for fibers, the spinnability is good, the pack pressure rise is suppressed, and high-quality spun-dyed fibers can be produced with good productivity.

Continued front page    F-term (reference) 4F070 AA47 AB09 AB21 AC04 AC40                       AC65 AD04 AD06 AE04 FA12                       FB04 FC05                 4J002 CF051 DA036 FB236 FD096                       GK00

Claims (10)

[Claims] 1. A polyester resin composition containing polytrimethylene terephthalate as a main component, wherein the carbon black having benzoic acid adsorbed on the surface thereof is contained in an amount of 5 to 50% by weight based on the total weight of the resin composition. And a polytrimethylene terephthalate resin composition having a cyclic dimer content of less than 1%. 2. The average particle size of carbon black is 10 to 10.
The polytrimethylene terephthalate resin composition according to claim 1, which is in a range of 50 nm. 3. The longest particle size of carbon black is 0.2 m.
The polytrimethylene terephthalate resin composition according to claim 1, wherein the content of coarse particles exceeding m is less than 1/200 g powder. 4. The iodine adsorption amount to carbon black specified in ASTM D1510 is 80 to 200 mg / g.
The polytrimethylene terephthalate resin composition according to claim 1, which is 5. The polytrimethylene terephthalate resin composition according to claim 1, wherein the adsorption amount of benzoic acid is 0.1 to 5% by weight based on the weight of carbon black. 6. An intrinsic viscosity of 0.7 to 0.9 and a color tone b
Is in the range of 2 to 6, wherein the polytrimethylene terephthalate resin composition according to claim 1. 7. A method for producing a polyester resin composition containing carbon black at a high concentration by kneading a carbon black pigment and a polyester resin containing polytrimethylene terephthalate as a main component in a kneading extruder. A powdered polymer having an average particle diameter of 2 mm or less is used as the polyester resin, and carbon black pigment having an average particle diameter in the range of 10 to 50 nm and benzoic acid are premixed in the range of 100 to 160 ° C. A method for producing a master dyed master polyester, which comprises using and kneading by supplying to a kneading extruder. 8. The content of coarse particles having a longest particle size exceeding 0.2 mm as a carbon black pigment is 1/200 g.
The manufacturing method according to claim 7, wherein the powder is less than powder. 9. ASTM as carbon black pigment
Iodine adsorption amount specified in D1510 is 80-200 mg
The production method according to claim 7, wherein carbon black having an amount of / g is used. 10. The following formula is satisfied when the pre-mixing time (t) (min) is B and C, the relative weights of benzoic acid and carbon black are respectively, and the pre-mixing temperature is T (° C.). 7. The method for producing polytrimethylene terephthalate according to 7. [Equation 1]